Fluid-operated gage.



No. 794.677. PATENTED JULY 11, 1905.

- M. MARTIN.

FLUID OPERATED GAGE.

APPLICATION FILED AUG. 31,1903.

UNITED STATES Patented July 11, 1905.

PATENT OFFICE.

MORRIS MARTIN, OF MALDEN, MASSACHUSETTS, ASSIGNOR TO GEORGE I/V. GREGORY, TRUSTEE, OF BOSTON, MASSACHUSETTS.

FLUID-OPERATED GAG E.

SPECIFICATION forming part of Letters Patent No. 794,677, dated July 11, 1905 Application filed August 31, 1903. Serial No. 171,318.

To all whom it may concern.-

Be it known that I, MoRRIs MARTIN, a citizen of the United States, residing at Malden, in the county of Middlesex and State of Massachusetts, have invented an Improvement in F luid-Operated Gages, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention has for its object the production of a novel fluid-operated gage adapted to be attached to any receptacle containing fluid such, for instance, as a tank containing gasolene under pressure or a boiler containing waterwhich may be used with great advantage in connection with automobiles.

The essential elements of my novel gage are two permanent magnets having their axes of rotation coincident in the same vertical plane, one of the magnets, which may be called the primary magnet, being controlled as to its rotation by a float, while the second magnet, which may be called the secondary magnet, is shown as a magnetic needle, such as used in compasses. These two magnets are rotatable for a substantially full or less than a full rotation in chambers, and the chamber containing the secondary magnet or magnetic needle is substantially hermetically sealed, so that any gas or fumes arising from gasolene cannot get thereinto to coat or blur the glass used to cover the magnetic needle, which gas would prevent the magnetic needle from being seen easily. V

Figure 1, in vertical section, shows one of my novel gages applied to part of the shell of a tank, which may be of usual form and contain gasolene or water. Fig. 2 is a top or plan view of Fig. 1. Fig. 3 shows my gage adapted for use as a steam-gage, and Fig. 4 shows a modification to be described.

Referring to the drawings, A represents part of a tank, boiler, or other fluid-receptacle provided with a curb B, securely held therein air, gas, and fluid tight. This curb, as shown, has within it a shoulder Z) and a screw-threaded part b, above which in turn is another shoulder, and above the second shoulder there is a second screw-threaded part herein chosen to embody my invention there are slots that embrace the guiding means and a central slot that is forked over the primarymagnet carrier, shown as a spiral shaft d, the lower end of which is represented as seated in a tie-rod CZ. The upper end of the spiral shaft has a journal (Z that, extended through the plate 0, has secured to it in suitable man ner a permanent primary magnet 61 In the construction shown the spiral shaft d is free to be turned by the rising and falling of the float as the level of the fluid varies. Instead of the spiral shaft shown I may employ any other suitable means controlled by a float that will cause one revolution or any portion of a revolution of the primary magnet through change of level of the liquid in the tank.

The flanged upper end of the plate 0 sustains a packing e, on which is laid a plate f, having at its center an upright point for supporting the secondary magnet, shown as a magnetic needle 12. This plate, pin, and needle are such as commonly used in compasses and may be of any material, shape, andisize. The plate f will have marked or otherwise displayed upon it either numerals, figures, or any other desired indications to represent whether the tank is full, quarter-full, half-full, or three-quarters full, or it may be figures to show the quantity of fluid in the can by measurement. The needle is retained operatively on the point through the intervention of a glass it, shown as resting on a packing 2, the upper side of the glass being acted upon by a threaded collar m. (See Fig. 1.) This glass may and preferably will be of a nature to magnify the marks on the indicator.

It will be understood in a gage of this character that the gage must be sealed gas and steam tight into the tank, and, further, that the space in which moves the secondary magnet or magnetic needle under the glass must be absolutely gas and steam tight, so that under no considerations can steam or gasolene fumes enter the space in which the needle moves, as the would obscure the glass, so that the indication-marks could not be read. This is accon'iplished by the packing a and the threaded ring screwed down on the plate f against the packing.

A gage of this kind is of great value when applied to a gasolene or fluid tank of, say, an automobile in which if the fluid that can be carried only in limited quantities should fail accident to life is liable to happen. At the present time the quantity of fluid in fluidchambers of automobiles is usually ascertained by removing the cap through which the fluid is filled into the tank and measuring the quantity of fluid with a stick or rod.

It will be noticed that the needle coacting with the ligured plate to indicate the amount of fluid in the tank is disassociated, as it were, from the tank, so that under no considerations can any fumes rising from gasolene come in contact with the needle, the glass, or the figured side of the plate, and consequently it may always be readily seen where the pointer stands, and the under side of the glass will be clean. This would not be the case if the needle were mounted upon the red, as is customary in liquid-gages.

The permanent or primary magnet in its rotation due to the change of level of the float will attract the secondary magnet or magnetic needle, so that the needle and the magnet will remain substantially parallel, the south pole of the primary magnet attracting the north pole of the needle and the north pole of the magnet the south pole of the needle.

By the employment of two magnets rather than one magnet and a steel needle which is not magnetized the rotations of the primary and secondary magnets are always alike, and under no circumstances of use can the magnetic needle be made to jump or fly away from the control of the positive magnet. I disclaim the use of a magnet and a steel needle which is not magnetized, so as to make of it a secondary magnet. In my invention I make use of the natural laws of attraction and repulsion of the magnetic poles to control unerringly the position of the magnetic needles which must be moved and accurately positioned by the positive magnet, which itself is controlled positively by the float.

My novel device may be adapted with great advantage as a steam-gage for steam-boilers and add materially to the safety thereof, for the reason that with my gage I do away with any glass in contact with the water and also do away with glass tubes, plates, &e., that may be discolored by the action of the water. In usual water-gages the glass after a short time becomes coated with impurities of the water and it becomes difficult to detect the water-line in the tube except by the closest inspection, which some people are not able to give.

In Fig. 3 I have shown two pipes 7) p in communication with a boiler C, the outer ends of said pipes entering a pipe p", having at its lower end a petcock, said pipe constituting a small tank, in practice the parts shown in the sectional view Fig. 1, so that water or other fluid in the boiler may ente and rise and fall in the tube 7) and turn the float, as described, causing the magnetic needle fully represented in Fig. l) to indicate at the upper end of the tube the condition of the water in the boiler.

NVhereas for the most perfect results the magnetic needle ought to be made as a portion of the gage, yet it would be obvious to those skilled in the art that I might set a coinpass-box with its usual needle and glass, the bottom of the box being suitably marked to indicate quantities of fluid, into the curb l3, letting the bottom of the compass-box be sustained therein sligl'itly above the path of movement of the magnet, and. I consider such a variation as within the scope of my invention.

Herein the plate f sustaining the magnetic needle is not h'xed with relation to the plate from which depends the float-guide, and con sequently the plate f may be adjusted relatively to the plate 0 to provide for placing the index-lines or plate f in just the proper position with relation to the magnet after the lat ter has been placed in the tank. When the clamping-ring is relaxed, the plate f may be freely adjusted.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. A tank, a curb secured thereto gas and fluid tight and provided with a shoulder, a plate sustaining float-guiding means and supported upon said shoulder, a float movable vertically on said float-guiding means as the quantity of fluid in the tank varies, a primary magnet, means controlled by the float to turn said primary magnet and a secondary magnet exposed to view above the primary magnet and moved thereby to indicate changes of fluid in the tank.

2. In a gage, a plate, float-guiding means below said plate, a rock-shaft, a float movable longitudinally of said rock-shaft and adapted to turn the same as the fluid in the tank varies in quantity, the upper end of said shaft above said plate having attached to it a permanent magnet, and a magnetic needle sustained above said magnet and separated therefrom by a metallic diaphragm, the rotation of the magnet moving the magnetic needle in unison with it.

3. A gage comprising a curb, a magnetic needle, a plate having a pivot to sustain said needle, a glass to prevent the magnet from falling off its pivot, said plate and glass having packing-joints with the curb a permanent magnet, its carrying-shaft, and a float for turning said shaft as the level of a fluid sustaining the float varies.

4:. A gage comprising a curb having an interior shoulder, float-guiding means, a plate carrying said float-guiding means and supported upon said interior shoulder, a second plate disposed above the first-named plate and carrying a magnetic needle, means for forming a fluid-tight joint between the edges of the said plates to hermetically seal the chamber containing the needle, and a permanent magnet and a float for operating the same.

5. A gage comprising a curb having an interior shoulder, float-guiding means, a plate carrying said float-guidingmeans and supported upon said interior shoulder, a second plate disposed above the first-named plate and carrying a magnetic needle, packing disposed between the edges of said plates, means for forcing the plates against the packing to form a fluid-tight joint, a permanent magnet below said needle, and a float for operating the same.

6. A gage comprising a curb having interior shoulders, float-guiding means, a plate carrying said float-guiding means and supported upon one of said interior shoulders, a second plate disposed above the first-named plate and carrying a magnetic needle, a glass disposed above the needle and supported upon another of said interior shoulders, and means for forming a fluid-tight joint between the edges of said plates.

7. The combination with a tank having a curb attached thereto gas and fluid tight, a plate having a float-guide of smaller diameter than the opening in the curb, a step at the foot of said float-guide, said float-guide and float being adapted to be put into the tank through said curb, a rock-shaft mounted at its lower end in said step and provided at its upper end above said plate with a permanent magnet, and another plate sustained loosely by said curb, a pivoted magnetic needle above said plate, and means to clamp said second plate fixedly with relation to the curb in any position in which said plate may be left when applied to the tank.

8. In a fluid-gage, a float-guide presenting at its upper end a plate and provided at its lower end with a step, a rock-shaft sustained at its lower end in said step and provided at its upper end above said plate with a permanent magnet, another plate having a pivot on its upper side, a magnetic needle mounted on said pivot, and a float guided by said floatguide and revolving said shaft and with it said permanent magnet close to the under side of the plate supporting said magnetic needle, the magnetic force exerted by the magnet working through only the plate sustaining the magnetic needle to turn the latter in unison with the magnet.

9. A tank having a threaded curb attached thereto gas and fluid tight, a plate sustained loosely by said curb and having a connected depending float-guide provided with a float of smaller diameter than the opening through said curb that the guide and float may be readily inserted in the tank through the curb at its upper end, a rock-shaft having a connected magnet, a float controlled by said floatguide and adapted to revolve the rock-shaft and magnet as the quantity of fluid varies in the tank, a magnetic needle, means to sustain said needle, and means to retain the needlesustaining means in adjusted position above said magnet, the magnet in its rotation moving the magnetic needle in unison with it.

p In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

MORRIS MARTIN.

Witnesses:

JOHN (J. EDWARDS, MARGARET A. DUNN. 

